Fit body, fit brain: 5 ways exercise makes you smarter

When it comes to exercise motivation, most of us cite looking #fitspo-worthy or nailing a PB at an event. But with the rise of brain scan technology, scientists are increasingly proving that the mental health benefits are perhaps the best exercise benefit of all.

1. Running improves your learning capacity

If you've got a big exam or work deadline coming up, then you might want to pound the pavement as much as you hit the books.

Long distance running has been found to increase the generation of neurons in the brain — moreso than strength training or high-intensity interval training.

2. Fitness leads to more flexible brains

If you want to remain curious and open to new ideas, then make sure you're getting regular exercise.

Italian researchers have found that exercising enhances the neuroplasticity of the visual cortex of the brain.

While the University of Pisa researchers were particularly interested in how this could help people with a lazy eye, their study is just one of many that establish a link between exercise and keeping our brain dynamic and adaptable.

3. It works like an antidepressant

Doing vigorous exercise could soon be prescribed to people suffering depression instead of common antidepressants called SSRIs.

People with depression often have depleted levels of the transmitters glutamate and GABA, but US researchers have found that doing 25 minutes of exercise getting the heartrate up to about 85 percent of its capacity actually spiked the transmitter levels.

4. Fitter people stay smarter in old age

A Japanese brain scan study showed that the brains of fit old men were in a similar state to that of younger men.

Typically when we're younger, we tend to favour the left side of our prefrontal cortex for understanding and recognising things but as we age, we tend to use the right side more.

The researchers found that older people who have a good level of fitness are more likely to use the left, youth-associated side of their brain.

"There is some evidence to support the theory that fitter adults are able to better maintain this white matter than less fit adults, but further study is needed to confirm this theory."

5. Strength training slows dementia

While some studies have found cardio training is best for the brain, Canadian researchers say that strength training is key for helping sufferers of dementia improve their memory and executive functioning.

"Weight training, even as little as once or twice a week, can minimise the rate of cognitive decline and change the disease course."

So how much do you need to exercise for a powerful brain?

While Australian government guidelines recommend 2.5 to 5 hours of moderate intensity exercise or 75 to 150 minutes of vigorous activity a week for good health, Harvard University researchers suggest three to five times that much — or a little over an hour a day — is ideal for a long, healthy life.

They pooled data from more than 661,000 adults and compared exercise rates with chance of death and found those who walked over an hour a day lowered their risk of premature death by 39 percent.

As for what kind of exercise to do — your best bet would be to get a combo of cardio and strength-based activities to make sure you've covered all brain, and body, bases.